GB1478433A - Operating mechanism for an electric circuit interrupter - Google Patents

Abstract

1478433 Automatic circuit breakers MERLIN GERIN 3 April 1975 [12 April 1974] 13798/75 Heading H1N An operating mechanism for a circuit breaker which performs a cycle of opening and closing a circuit without intermediate resetting comprises a first crank arm 22 on a shaft 18. which operates the contacts of the circuit breaker and is latched by a latch 64, and a second crank arm 20 on a shaft 16 adapted to be operated by a control member and latched by a latch 62, both crank arms being mounted between parallel plates 12 and connected by a lost motion connection rod 48 so that the interconnections between the crank arms, side plates and connection rod lie at the apices of a quadrilateral which has one side of variable length and which is deformed under the action of a single compression spring 36 inserted between the crank arms and having a different line of action from the connection rod, this spring providing the energy to perform the opening and closing cycle. The spring 36 passes over a guiding bar 38 one of whose ends is rotatably mounted on the second crank arm and whose other end is rotatably and slidably mounted on the first crank arm. Opening and closing of the circuit breaker are produced by reciprocating rotation of the first crank arm 22, release of latch 64 to free crank arm 22 allowing anticlockwise rotation of the crank arm 22 under the influence of spring 36 to close the contacts, the second crank arm 20 being blocked during this time by latch 62, whilst when latch 62 is released it allows crank arm 20 to rotate in a clockwise direction to drive crank arm 22 through rod 48 to open the contacts. The latches 62, 64 are controlled by solenoid or manual control. Resetting after the cycle is manual or automatic. An interlock arrangement may be provided, Fig. 5 not shown, to control the latches causing opening and closing of the circuit.